Sedna SE-B2K USB VoIP

Hello, someon used this box also with Sip? Some say it is only for skype and then on the webpages they say also for Sip, gtalk, msn, etc, I am alittle confused, i don`t ant to order it when am not sure if it isreally usable with sip too, and if I will not have a problem when using it with Ubuntu.
I also would like to know if I can dial from the phone or if it is difficult to set up for dialing from the pstn phone connected to it?
Thank you.

The device probably comes with MS Windows software to work with Skype. It can also be used with SIP more or less as a usb sound card that a phone will plug into. Some of these devices work with X-Lite a little more completely I think. With Linux you can expect the device to work again as a usb sound card that a phone will plug into assuming that it uses the standard drivers.
It it is like the device that I have then PSTN should work normally (including keypad) and the computer does not have to be running.